[2012.5.18] We publish a paper "High Yield Recombinant Expression, Characterization and Homology Modeling of Two Types ofCis-epoxysuccinic Acid Hydrolases" onProteinJ.now. Thecis-epoxysuccinate hydrolases (CESHs), members of epoxide hydrolase, catalyzecis-epoxysuccinic acid hydrolysis to form D(-)-tartaric acid or L(+)-tartaric acid which are important chemicals with broad scientific and industrial applications. Two types of CESHs (CESH[D] and CESH[L], producing D(-)- and L(+)-tartaric acids, respectively) have been reported with low yield and complicated purification procedure in previous studies. In our paper, both CESH[D] and CESH[L] were recombinantly expressed inE. coliwith high yield and recovery. We successfully used codon-optimized synthesized genes and His6-tag fusion protein to obtain high expression and fast purification. The purified recombinant proteins exhibited similar properties as the native proteins purified from the original species, and the only exception is that the recombinant CESH[L] showed a slightly higher optimal temperature than that of native CESH[L]. Homology modeling of the two CESHs indicates that CESH[L] and CESH[D] have completely different structures and active site residues. CESH[L] adopted a typical alpha/beta-hydrolase fold with a cap domain and a core domain, and conserved catalytically important residues consist a catalytic pocket at the interface of two functional domains. CESH[D] possessed a unique TIM barrel fold composed of 8 alpha-helices and 8 beta-strands, and 2 extra short alpha-helices exist on the top and bottom of the barrel, respectively. A divalent metal ion was found in CESH[D] by homology modeling and activity experiments. The metal ion, preferred to be zinc, is necessary to the activity of CESH[D]. Our work provides the basis to the stability and protein engineering studies, as well as the structural insight of the catalytic mechanisms of the two CESHs, which will be helpful to the industrial productions and other applications.
The first author Gu-zhen Cui is a Ph.D. candidate student. The Metabolomics Group leader Prof. Dr. Qiu Cui is the corresponding author.This work is supported by One-hundred-Talented-People program (KSCX2-YW-G-066) from the Chinese Academy of Sciences, and the National Natural Science Foundation of China (Grant No. 30970050).
NCBI PubMed
Gu-Zhen Cui, Shan Wang, Yifei Li, Yi-Jun Tian, Yingang Feng, and Qiu Cui* (2012) High yield recombinant expression, characterization and homology modeling of two types of cis-epoxysuccinic acid hydrolases.Protein J.31, 432-438.Full Text Link (Publisher website)
